Cardiovascular research program concerns studies of cardiac muscle and its blood supply. These studies are being performed at both a clinical and at a basic level. The mechanics and hemodynamics of cardiac muscle will be studied in intact man and dogs with particular emphasis on force velocity, length relations and dynamic morphology of contraction as determined by angiographic means. Blood flow to the myocardium will be studied in man and in the experimental animal, using both direct and diffusible indicator techniques. These studies will analyze both the topographic and the depth distribution of blood flow under a variety of normal and pathological conditions. Studies in coronary heart disease will include its early detection and modification by therapeutic intervention and the use of experimental models. Cardiac metabolism will be studied both in intact man and in the isolated preparation and will range from analysis of the effect of various carbohydrates on metabolism to studies of amino-acid exchange and protein synthesis within the cardiac cell, including factors which regulate such synthesis. There will be additional studies related to excitation contraction coupling and to specific membrane enzymes in the isolated cardiac muscle preparation.